[release/8.0] Fill out FORMATETC on MultilineStringEditor Paste (#11113)

* Fill out FORMATETC on multistringeditor paste

* Add debug assert

---------

Co-authored-by: Loni Tra <[email protected]>

Author: github-actions[bot]

src/System.Windows.Forms.Design/src/System/ComponentModel/Design/MultilineStringEditor.OleCallback.cs

@@ -125,17 +125,23 @@ public HRESULT QueryAcceptData(Com.IDataObject* lpdataobj, ushort* lpcfFormat, R
 
                 FORMATETC textFormat = new()
                 {
-                    cfFormat = (ushort)CLIPBOARD_FORMAT.CF_TEXT
+                    cfFormat = (ushort)CLIPBOARD_FORMAT.CF_TEXT,
+                    dwAspect = (uint)DVASPECT.DVASPECT_CONTENT,
+                    lindex = -1,
+                    tymed = (uint)(TYMED.TYMED_HGLOBAL | TYMED.TYMED_ISTREAM | TYMED.TYMED_GDI)
                 };
 
                 FORMATETC unicodeFormat = new()
                 {
-                    cfFormat = (ushort)CLIPBOARD_FORMAT.CF_UNICODETEXT
+                    cfFormat = (ushort)CLIPBOARD_FORMAT.CF_UNICODETEXT,
+                    dwAspect = (uint)DVASPECT.DVASPECT_CONTENT,
+                    lindex = -1,
+                    tymed = (uint)(TYMED.TYMED_HGLOBAL | TYMED.TYMED_ISTREAM | TYMED.TYMED_GDI)
                 };
 
-                return lpdataobj->QueryGetData(&textFormat).Succeeded || lpdataobj->QueryGetData(&unicodeFormat).Succeeded
-                    ? HRESULT.S_OK
-                    : HRESULT.E_FAIL;
+                bool success = lpdataobj->QueryGetData(&textFormat).Succeeded || lpdataobj->QueryGetData(&unicodeFormat).Succeeded;
+                Debug.Assert(success);
+                return success ? HRESULT.S_OK : HRESULT.E_FAIL;
             }
 
             return HRESULT.E_NOTIMPL;